The solution in Solved: Local Install: "No WARC Files, assuming crawl failed. Quitting" - #2 by kramski also applies here.
With access to a log file, this “Crash” turned out to be just an expired login in the browser profile, so the crawler was redirected to a login page and could not find any matching URLs.
The message “Crawler Instance Crashed” seems a little over-dramatic in this case.